Hydraulic Lifter Noise – The Fix

When it comes to building engines, those equipped with hydraulic roller lifters offer major advantages to budget-conscious car crafters. Starting in 1987 with passenger-car small-blocks, including the Corvette and Camaro, Chevrolet began gearing engines with hydraulic roller lifters and cams. Ford was actually a year ahead of Chevrolet, first equipping the 5.0L Mustangs with hydraulic roller cams in 1986. We don’t need to go into all the advantages of roller lifters here, as we’re more concerned with adapting them to a performance engine. The big plus with roller lifters is, unlike their flat-faced predecessors, they can be reused on both new and used roller cams with little fear of failure. But while it may seem as though you can use hydraulic roller lifters repeatedly with impunity, we’ve discovered that’s not entirely true. Most discussions regarding scouting used roller lifters concentrate on the roller bearings and hydraulic lifter noise, which is important, but the lifter’s internal check valve is an area that is also susceptible to failure.

Buttoning up a recent budget small-block Chevy engine build, we tried a set of used hydraulic roller lifters that appeared to be in good shape. We disassembled all 16 and cleaned the internal pistons, being careful to do only one at a time. But after starting the engine, it was clear from the loud clattering that we had a problem – hydraulic lifter noise. Immediately after engine shutdown, we yanked the valve covers and discovered that six of the lifters could very easily be depressed (the remaining lifters appeared to be good). Initially, we thought excessive clearance between the lifter piston and body was the problem, but after talking with Mike Golding of Gaterman Products, who sells high-quality performance roller lifters, we learned that dirt or debris in the check valve inside the hydraulic piston is more likely the culprit. Sometimes, the caged check ball can be cleaned with a shot of carb cleaner and high-pressure air to restore its proper seal. If you connect the top of the piston to a vacuum source, you’ll see that any lifter that can’t maintain a vacuum has obvious check-ball leakage and will likely cause hydraulic lifter noise. Of course, performing this test requires disassembling each lifter, making the purchase of used hydraulic roller lifters with an unknown background a bit of a crapshoot. Check-valve problems are generally tied to engines that have not been properly maintained. While you could experiment with multiple sets of lifters to find 16 good ones, that’s a lot of work, especially when the task involves removing the intake manifold. Golding also warns that the pistons used inside the hydraulic lifter are carefully sized to within 50 millionths (0.000050) of an inch. That means you should not mix lifter bodies and internal pistons. If you disassemble a hydraulic lifter, you should always keep the internal parts together for reassembly.

Hydraulic lifter noise can also be aggravated by excessive valvespring pressure. The Dart heads on our small-block use 1.250-inch-diameter single springs with 110 pounds of seat load and around 280 pounds over the nose. This seat pressure is about 20 to 30 pounds higher than production springs and could contribute to noisy lifters. The bottom line is that a high-quality lifter with more accurate clearances and clean check valves will allow higher spring loads without additional noise. But also be aware that performance camshafts will often create some noise, which is a direct result of the more aggressive lobe design rather than any fault of the lifter. We’ve included several sources for hydraulic roller lifters along with some other performance lifter recommendations to help you find the right fit for your application.